Currently, there are 20 major running shoe makers competing in the US running shoe market. They include some of the biggest names in sporting goods and apparel such as Nike, Adidas, and Under Armour as well as companies that specialize in running shoes such as New Balance, Saucony (a subsidiary of Wolverine), and Brooks. The running shoe segment accounts for 55% of all athletic shoe sales in the US or about 220 million pairs per year. The athletic shoe market is not very capital intensive. IBISWorld rates the industry as "low" in capital intensity - suggesting that the minimum efficient scale is low as well. In order for all 20 of the major companies to operate efficiently, minimum efficient scale must be ___________ pairs per year or less.

20 million

22 million

11 million

5 million

Please do fast and correct

** I need correct answer***